Building railway transport resilience to alpine hazards

Issue topic

The transportation system in Alpine countries plays a vital role in the European transit of passengers and freights from north to south and east to west. In addition, transportation lines are essential for the accessibility of lateral valleys and their economic welfare. Climate change will likely increase (some) alpine hazards and risks. In mountain areas, extreme weather events regularly trigger hazardous and torrential processes like different kinds of flooding, landslides or avalanches and their intermixtures. As transportation infrastructure has a bottleneck function in the Alps, this case study will focus on enhancing resilience of a transportation network in a multi-hazard context and on reducing adverse effects of natural hazards in the transportation infrastructure in Austria. For this, two tracks will be investigated in detail.

Storyline

The Austrian Alps host a beautiful landscape of mountains, valleys and rivers. Although being ideal for outdoor activities, it implies challenging engineering tasks for the construction and operation of the railway network. Over the years, given their central position in Europe, Alpine railways became key for freight transport and travellers with growing economic perspectives.

Yet, torrents, mudflow, rock fall, avalanches and floods lead to regular disruption of railway tracks, causing large economic damages and temporary closures of line sections as railway tracks and bridges can be washed away or can be severely damaged.

The Austrian Railway Infrastructure AG (ÖBB Infra), along with the civil and governmental partners are left with the difficult and costly mandate to assess risks, take preventive measures, and ensure the continuous operation of the network. Although done with dedication, the risk partnership suffers from mixed information exchange and cost-sharing divergence.

Improvement of structural and non-structural risk management

ENHANCE partners analyse and reinforce the existing partnership. It builds upon both structural (cost sharing) and non-structural measures (information exchange) to improve decision-making process with regard to Alpine hazards.

On one hand, given limited time and budget, effectiveness of preventive measures is necessary. ENHANCE provides improved knowledge for decision-making with a broader approach than the commonly applied cost-benefit analysis, by applying a multi-criteria analysis. On the other hand, partners deliver new insights on the current and future risks, as the hazard situation might change due to climate change.

As part of its commitments, ENHANCE brings in-depth study of the hazards through:
• A detailed risk assessment for floods and debris flows at various locations for railway tracks;
• A comparison of the frequency of critical events with the number of floods and debris flows;
• An analysis of how improved risk information will influence the cooperation between stakeholders and decisions to close tracks, or to implement risk reducing protection measures.

By analysing existing processes and combining them with new risk projections, ENHANCE provides a robust handgrip to secure current and future resilience in the Alpine railway lines whilst paying attention to costs shared by the different actors.

ENHANCE facilitates a stakeholder driven approach, where stakeholders in risk management together with research jointly seek improved multi-sector partnerships in a participatory way.

State of play

• The Austrian Railway Infrastructure AG (ÖBB Infra) is the key player for all partnerships as the state of Austria is always financing projects for risk reduction. Nonetheless, the project found out that the Ministry of Transport is less involved in the mitigation of natural hazards when it comes to railways.
• The case study is currently developing a classification of possible damages to railway infrastructure and assesses the availability of railway lines in case of natural hazards.

Objectives

This case study will develop vulnerability/damage functions for key infrastructure elements and perform a quantitative risk analysis at selected railway tracks as a basis for improved risk management procedures. Furthermore, risk management partnerships will be identified and analysed.

To respond to the need for information on potential risk hot spots and expected flood damage, ENHANCE partners from the University of Potsdam have developed an empirical modelling approach. It estimates direct structural damage to railway infrastructure and associated financial losses. The study uses the 2006 March River flood that occurred at the Austrian Northern Railway as a case study.